@media all and (orientation: landscape) {
  /* 滚动条及横屏显示 */
  ::-webkit-scrollbar-track-piece {
    -webkit-border-radius: 0
  }
  ::-webkit-scrollbar {
    width: 5px;
    height: 10px
  }
  ::-webkit-scrollbar-thumb {
    height: 10px;
    background-color: #b8b8b8;
    -webkit-border-radius: 6px;
    outline-offset: -2px;
    filter: alpha(opacity = 50);
    -moz-opacity: 0.5;
    -khtml-opacity: 0.5;
    opacity: 0.5
  }
  ::-webkit-scrollbar-thumb:hover {
    height: 10px;
    background-color: #878987;
    -webkit-border-radius: 6px
  }

  html,
  body {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 100%;
    padding: 0;
    margin: 0;
  }
  html::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background: #333;
    z-index: -1;
  }
  html::after {
    content: "\4E3A\4E86\66F4\597D\7684\4F53\9A8C\FF0C\8BF7\5C06\624B\673A\7AD6\8FC7\6765";
    text-align: center;
    font-size: 16px;
    color: #fff;
    position: absolute;
    top: 50%;
    left: 0;
    height: 30px;
    width: 100%;
    margin-top: 50px;
    z-index: -1;
  }
  body::before {
    content: "";
    position: absolute;
    z-index: -1;
    height: 200px;
    width: 100px;
    left: 50%;
    top: 50%;
    margin: -140px 0 0 -50px;
    color: #fff;
    background-image: url("");
    background-repeat: no-repeat;
    background-position: center center;
    background-size: 100px auto;
    -webkit-transform: rotateZ(-90deg);
  }
}
@media all and (orientation: portrait) {
  html,
  body {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 100%;
    padding: 0;
    margin: 0;
  }
  html::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background: #333;
    z-index: -1;
  }
  html::after {
    content: "\4E3A\4E86\66F4\597D\7684\4F53\9A8C\FF0C\8BF7\5C06\624B\673A\6A2A\8FC7\6765";
    position: absolute;
    top: 50%;
    left: 0;
    height: 30px;
    width: 100%;
    margin-top: 30px;
    z-index: -1;
    text-align: center;
    font-size: 16px;
    color: #fff;
  }
  body::before {
    content: "";
    position: absolute;
    z-index: -1;
    height: 200px;
    width: 100px;
    left: 50%;
    top: 50%;
    margin: -160px 0 0 -50px;
    color: #fff;
    background-image: url("");
    background-repeat: no-repeat;
    background-position: center center;
    background-size: 100px auto;
  }
}

.App-header {
  min-height: 100vh;
  font-size: calc(10px + 2vmin);
}
.flex {
  display: flex;
}
.F_center {
  justify-content: center;
}
.center{
  text-align: center;
}
.flexB {
  justify-content: space-between;
}
.flexA {
  justify-content: space-around;
}
.over {
  overflow: hidden;
}
.floatL {
  float: left;
  height: 100%;
}
